Ecler DPA2500T Service Manual Download Page 30

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51-0153-0100 EP04-05-05 DPA2500T DPA4000T.doc 1 of 3

Assembled Amplifier.

PRELIMINARY:

Set the BRIDGE-STEREO selection switch to STEREO.

Check the

Ground Link

switch.

Keep the subsonic filter, at the input stage circuitry, set to OFF.

Be sure that the correct cable types are used.

Connect the power amplifier mains plug to a 230Vac variac output, and leave it on its 0V position.

Keep an ammeter nearby (DC 10A range), in order to verify the current consumption adjustments.

VERIFICATION:

Switch the tested unit's Power main switch to ON, without applying any input signal.

Remove the protection fuse of the positive power supply, and place instead a 10A DC ranged
ammeter. Keep the module's output signal insight by using an oscilloscope, selecting a 10V/div
vertical scale and 5ms/div time base.

Note:

In case of doubt, if you only want to feed one channel

while verifying the current consumption, simply do not insert the mains protection fuse in the other
channel.

Slowly increase the variac’s output until it reaches the unit’s nominal mains voltage, and if an
excessive current consumption is detected (current flow above 800mA), stop the testing procedure
immediately and try to identify the failure. Once the nominal mains voltage is reached, wait for a
minute and verify that the current consumption adjustments remain correct: 300mA for DPA4000T,
190mA for DPA2500T. If these values have changed, rectify them. Once adjusted, seal the
potentiometer with fixing lacquer.

Caution! The unit’s power supply will be charged! Before removing the ammeter and
replacing the fuse, it is strongly recommended to completely discharge the unit's power
supply by applying a 1KHz 0dB input signal and connecting 4

Ω

load impedances to the

amplifier’s output, and reduce the unit’s mains voltage to 0V by turning down the variac’s
output.

Repeat this procedure on the other channel.

Once the adjustments are done, turn on again the unit by switching over its main power switch, and
verify the STANDBY period lasts approximately 10 seconds, the

clip

and

protect

indicating LED's

light up, and also the cooling fans run up to their maximum running speed.

Verify both XLR-type inputs, the

STK-OUTPUT

, their correspondent

signal present

indicator LED’s

and also check the correct functioning of the input signal attenuators, as their actuation range.

Verify the unit’s output power when working at nominal mains voltage (230Vac):

DPA4000T

1880W

86,7V

Ω

DPA2500T

1130W

67,2V

Ω

To verify the ANTICLIP function, increase the input signal level above 0dB and check that the
clipping output signal is smoothened. Check the CLIP indicator LED’s are lit, and, when reducing the
output signal level in 0,5 or 1dB, the CLIP LEDs turn off.

Verify the unit’s bandwith curve, with a 2KHz 0,5V input signal, should be linear between 20Hz and
20KHz without inducing any distortion to the output signal. Also check that when applying an input
signal up to 50KHz, the unit’s output level only decreases in 1 or 2dB, and no visible distortion is
observed.

Verify the BRIDGE operating mode. Switch over the BRIDGE-STEREO selector to BRIDGE, check
that both channels are achieving the same gain level when not loaded. In order to verify this, apply a
1KHz 0dB input signal to channel I and, with the volume potentiometer turned up to its maximum,

author:

J. Colomines

date:

051006

project:

EP04/05-05

product:

DPA2500T/4000T

ECLER

approved:

num:

51.0153